Posted on 11/11/2006 7:20:07 PM PST by cryptical
Embryonic stem cells, the controversial and versatile cells that seem able to do just about anything, have now expanded their repertoire into cancer prevention. A vaccine made from these cells shields mice against developing lung cancer under conditions thought to mimic the effects of smoking.
Safety concerns about injecting stem cells into humans mean that regulatory agencies are unlikely to approve human tests of the vaccine, says lead researcher John Eaton at the University of Louisville in Kentucky.
Nevertheless, he thinks the vaccine is worth testing in people at high risk of developing cancer, such as heavy smokers or people with certain genetic mutations.
Other researchers are more cautious. Cancer vaccines, particularly vaccines made from cells, are notoriously more effective in mice than people, says Jeffrey Weber, an immunotherapist at the University of Southern California in Los Angeles. "The idea is interesting, but the execution may be impossible," he says.
But both Weber and Eaton agree that the finding could lead to new ways to prevent or treat cancer.
A lot in common
Eaton's approach was inspired by the similarities between embryos, embryonic stem cells and tumours. "Embryos and tumours both grow as balls, they derive nutrients from the host, and they both express peculiar proteins - some of them in common," he says.
These shared proteins made Eaton think that a vaccine prompting an immune response to embryonic stem cells would also trigger an attack against tumours.
He and his colleagues injected mice with stem cells and gave the mice a booster shot ten days later. The researchers then transplanted lung cancer cells under the animals' skin — a standard animal model for the disease.
The stem-cell injection protected 20 out of 25 mice from developing tumours, whereas tumours grew in all unvaccinated mice.
"We were absolutely shocked," Eaton says.
Even more effective was a mixture of stem cells and cells engineered to make a molecule that stimulates the immune system. None of the mice given this vaccine developed tumours when implanted with cancer cells.
Eight of nine animals given this treatment were also protected from lung cancer induced by chemicals thought to mimic the effects of cigarette smoke.
Eaton is now testing his approach against other types of cancer. The findings were reported on 8 November at a meeting in Prague on 'Molecular targets and cancer therapeutics', sponsored by a consortium of cancer-research organizations from Europe and the United States.
Weird protein
Although the mice seemed to suffer no ill effects from the vaccine, Eaton admits that injecting live stem cells into people raises safety issues — such as whether the vaccine would make the body attack its own stem cells.
Eaton's team is now looking for the molecules on the embryonic stem cells that give the vaccine its tumour-killing power. That could potentially lead to more effective cancer vaccines with specific components.
The researchers have already discovered one such protein — found mainly in embryos, placentas and tumours. As yet, Eaton is unwilling to say much about it, except: "It's weird."
Looking for such molecules holds more promise than injecting stem cells themselves, says Weber.
Seems to me that Not Smoking would be an easier, cheaper and more ethical solution.
Of course you don't have to worry about that anyway since you are going to kill those mice long before the tissues are rejected.
I'm watching "Dawn of the Dead".
This was with mice. Do you oppose killing mouse embryos?
Somebody help me to understand this madness.
Adult stem cells have made great strides yet the scientists are not out there strumming up more funds to continue research on them. Yet embryonic stem cells have not been successful in humans but it's constantly talked about as though it really saves lives.
This information could be very useful to the research folks at Philip Morris when they are devising a new system of cigarette filtration.
Injecting a few of these stem cells into the next generation of the Micronite filter could do wonders I guess.
---Adult stem cells have made great strides yet the scientists are not out there strumming up more funds to continue research on them.---
Scientists ARE 'strumming up' more funds for adult stem cell research ... to the tune of hundreds of millions of dollars just from the federal government!
Plenty of funds, so they don't have to beg for them. Note the results that keep coming out.
Yet embryonic stem cells have not been successful in humans but it's constantly talked about as though it really saves lives.
Limited (and deteriorating) lines, and limited funding. Some folks around here seem to think that there's a secret cabal of liberals that are pushing embryonic stem cell research to make abortion profitable... A little tinfoil goes a long ways.
Somebody help me to understand this madness. Adult stem cells have made great strides yet the scientists are not out there strumming up more funds to continue research on them. Yet embryonic stem cells have not been successful in humans but it's constantly talked about as though it really saves lives.
If you really want to understand as opposed to making a rhetorical point, here goes: Adult stem cells have been used for many years, and are successful at treating certain diseases. Embryonic stem cells have been researched for a much shorter time, and hold the promise of curing diseases that adult stem cells don't. To a scientist, researching ESC is not to denigrate the value of ASC. The analogy I often use is penicillin and cipro - should they not have continued to research cipro "because cipro hasn't cured anything, and penicillin has already saved thousands of lives"?
I favor funding for both. I can understand ethical objections, but not the pretense that an (approximately) ten year old technology is worthless because it isn't as developed as a (approximately) 40 year old technology.
Another aspect of research is learning how cells develop. Not just in the sense that hESCs cure, but the knowledge we gain might lead to cures that are not dependent on the actual use of stem cells in the cure.
Embryonic stem cells, the controversial and versatile cells that seem able claimed to do just about anything, have now expanded their repertoire into cancer prevention.
There, fixed their immediately obvious bias.
"Embryonic stem cells, the controversial and versatile cells that seem able to do just about anything"
Well that's some jimdandy scientific reporting right there. So if I put stem cells next to a Pizza Hut will I get another Pizza Hut? They can do anything right?
Eventually we are going to have to rid ourselves of cannibals.
There, end of story.
--So, here's the deal ~ you invest your money in it.
There, end of story.--
End of Story? You have no problems with embryonic stem cell research if it is not your money?
Absolutely agreed. I've always been impressed by the part serendipity has played in scientific discovery.
Please do so WITHOUT MY MONEY you cannibalistic leach.
(That was just in case you failed to identify with the cannibals).
You are horribly behind. Embryonic stems cells may reverse global warming and may, in fact, be a viable renewable energy source.
--Please do so WITHOUT MY MONEY you cannibalistic leach.
(That was just in case you failed to identify with the cannibals).
"...hold the promise of curing diseases that adult stem cells don't."
Which diseases? Researching penicillin and cipro, did it depend on sacrificing a human embryo to find a cure.
If this isn't to keep abortion rare and legal, what benefit is it for cloning.
I do thank you for responding. I'll search it out to find the answers I need.
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